Patient motion during magnetic resonance imaging (MRI) examinations generates arte­facts which often render the resulting images clinically unusable. This significant problem hampers diagnosis and patient throughput, and cannot be solved by conditioning the patient. Our interdisciplinary project aims at the development of a fully MR-compatible optical motion tracking system in order to monitor uncontrolled spontaneous patient movements in the MR scanner. To ensure the visibility of the tracked body part, the tracking system has to be placed inside of the magnet bore. Hence, a multitude of technical components need to withstand and not disturb the strong uniform magnetic field. Since free space inside the magnet bore is extremely limited, the entire system has to be highly compact and requires the use of MR-compatible micro components.The talk introduces the problem of patient motion during an MRI scan, clarifies the technical concepts, visualizes the solutions, and demonstrates why an interdisciplinary team is mandatory for this research project.